Mosquito Spraying

The City posts spray zone maps online when spraying is announced.

Our contractor uses Aqua Perm-X UL 30-30(PDF, 246KB) . The active ingredient is Permethrin, applied at .0035 lbs. per acre using a truck-mounted spray rig. It is EPA approved(PDF, 330KB) for mosquito control. The West Nile Virus Technical Advisory Committee researched many products and chose this as the best option. Permethrin breaks down in sunlight and water, so it is recommended to water your gardens the morning after spraying.

These documents are provided for printing purposes. For assistance viewing or reading these documents, please contact the City's ADA Coordinator via email adacoordinator@fortcollins.gov or phone: 970-416-4254.

Permethrin affects insects when they eat it or touch it. It targets their nervous system. Permethrin is more toxic to insects than to people and dogs because insects can't break it down as quickly. Cats are more sensitive to permethrin than dogs or people.

Learn more about permethrin.

Stay indoors and keep doors and windows closed for 30-60 minutes after spraying. Bring pets inside, too.

Bring pets inside during spraying. Wait at least 30 minutes before going outside or letting pets out.

Cover water features with a tarp or sheet. The chemical is applied as a mist and won't go through the covering.

Cover your garden with a tarp or sheet. The chemical doesn't go through vegetable skin, so if your garden was uncovered, wash vegetables with warm soap and water to remove any residue.

Yes — most air conditioning systems, including portable room units, recirculate air already inside the home and do not take in outside air.

The City sends notifications only to people signed up for West Nile virus spraying community alerts through NOCO Alert.

• Email Alerts: Create an account. Under "My Alert Subscriptions," click "Community Alerts," then check "Fort Collins" and "West Nile Virus Spraying."
• Text Alerts: Text FCWNV to 888-777

NOCO Alert is managed by LETA911, the Governing Authority for 9-1-1 in Larimer County, Colorado. LETA911 oversees 9-1-1, equipment and programs funded by LETA, including community alerts for WNV spraying.

The City works with the Parks and Recreation departments, Poudre School District and Colorado State University on scheduled outdoor events in spray zones. We adjust routes to spray those areas later in the evening, after events end. If you have a private outdoor event that can't be moved or rescheduled (like a backyard wedding), we may be able to adjust timing. Call 970-416-2738 or email westnile@fortcollins.gov to discuss.

No. West Nile virus risk is a public health issue. The City only makes special accommodations for residents on the Colorado Department of Agriculture's Pesticide Sensitive Registry. More information is available on their website.

While the state doesn't guarantee municipalities will accommodate those on the registry, the City of Fort Collins follows this list in spray operations.

Businesses or laboratories can apply to opt out of spraying. Only commercial businesses with valid sales tax licenses that can prove long-term negative financial impact will be considered.

To apply:

• Complete the application form
• You'll be contacted within a week for an on-site inspection with the City's mosquito contractor, Vector Disease Control International (VDCI)
• Follow VDCI's inspection recommendations
• Once approved, you'll be added to the business opt-out list for one year